A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be
four times
doubled
halved
one fourth
Potentiometer measures the potential difference more accurately than a voltmeter because
it has a wire of high resistance
it has a wire of low resistance
it does not draw current from external circuit
it draws a heavy current from external circuit
The length of a potentiometer wire is 5 metres. An electron in this wire experiences a force of 4.8 × 10-19 newton, emf of the main cell used in potentiometer is
3 volt
15 volt
1.5 volt
5 volt
Four bulbs marked 40 W, 250 V are connected in series with 250 V mains, the total power consumed is
10 W
40 W
320 W
160 W
Fuse wire is a wire of
low resistance and low melting point
low resistance and high melting point
high resistance and high melting point
high resistance and low melting point
The resistance of a discharge tube is
zero
ohmic
non - ohmic
infinity
In india electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be
R
2R
The temperature of inversion of a thermocouple is 6200 C and the neutral temperature is 3000CWhat is the temperature of cold junction?
200c
3200c
-200c
400c
A 220 volt, 1000 watt bulb is connected across a 110 volt mains supply. The power consumed will be
750 watt
500 watt
250 watt
1000 watt
A storage battery is connected to the mains for charging with emf of 12.5 V. The internal resistance of the storage battery is 1 Ω. When the charging current is 0.5 A, the potential difference across the storage battery is
13 V
12.5 V
12 V
11.5 V
